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3 years ago

A star exhibits a parallax shift of .30” rounded to 2 significant digits. That star is ____ light years away.

Physics

1 answer:

Lubov Fominskaja [6]3 years ago

8 0

AnsweA 2.25 light years away

Explanation:

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What is the particle arrangement in a liquid

natali 33 [55]

Answer:

the particle arrangement in liquid are close together with no regular arrangement

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3 years ago

A dentist’s drill starts from rest. After 1.46 sof constant angular acceleration, it turns at arate of 27000 rev/min.Find the dr

Black_prince [1.1K]

Answer:

616.3 rad/s²

Explanation:

Given that

t= 1.46 s

Initial angular velocity ,ωi = 0 rad/s

Final angular velocity ωf= 27000 rev/min

Angular speed in the rad/s given as

$\omega_f=\dfrac{2\pi N}{60}\ rad/s$

Now by putting the values

$\omega_f=\dfrac{2\times 27000}{60}\ rad/s$

ωf=900 rad/s

We know that (if acceleration is constant)

ωf=ωi + α t

α=Angular acceleration

900 = 0 + α x 1.46

$\alpha=\dfrac{900}{1.46}\ rad/s^2\\\alpha=616.43\ rad/s^2$

Therefore the acceleration will be 616.3 rad/s²

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3 years ago

Three light bulbs are connected to a battery in a series circuit.How will the bulbs behave if the circuit is closed

Drupady [299]

The answer is

All the three light bulbs will glow

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6 0

3 years ago

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Alex17521 [72]

Answer

A. Metals A and metals B

Explanation

Heat transfer takes place whenever there is temperature difference. When two bodies of different temperatures are brought together, heat energy will move from one body to the other until equilibrium temperature is reached.

In our case, heat transfer will take place in all four metals.

Metal A will transfer heat to the water since it's temperature is higher than that of water.

Metal B will also transfer heat to the water since it's temperature is higher than that of water.

Metal C will get heat from the water since it's colder than the water.

Metal D will also get heat from the water since it is colder than water.

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3 years ago

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An engine draws energy from a hot reservoir with a temperature of 1250 K and exhausts energy into a cold reservoir with a temper

dimulka [17.4K]

Answer:

The power output of this engine is $P = 17.5 W$

The the maximum (Carnot) efficiency is $\eta_c = 0.7424$

The actual efficiency of this engine is $\eta _a = 0.46$

Explanation:

From the question we are told that

The temperature of the hot reservoir is $T_h = 1250 \ K$

The temperature of the cold reservoir is $T_c = 322 \ K$

The energy absorbed from the hot reservoir is $E_h = 1.37 *10^{5} \ J$

The energy exhausts into cold reservoir is $E_c = 7.4 *10^{4} J$

The power output is mathematically represented as

$P = \frac{W}{t}$

Where t is the time taken which we will assume to be 1 hour = 3600 s

W is the workdone which is mathematically represented as

$W = E_h -E_c$

substituting values

$W = 63000 J$

$P = \frac{63000}{3600}$

$P = 17.5 W$

The Carnot efficiency is mathematically represented as

$\eta_c = 1 - \frac{T_c}{T_h}$

$\eta_c = 1 - \frac{322}{1250}$

$\eta_c = 0.7424$

The actual efficiency is mathematically represented as

$\eta _a = \frac{W}{E_h}$

substituting values

$\eta _a = \frac{63000}{1.37*10^{5}}$

$\eta _a = 0.46$

7 0

3 years ago